She's gone from The Saturdays singer to star presenter and author. Rochelle Humes tells Katie Strick about standing in for Holly on This Morning, her new BBC show and embracing her natural hair

Rochelle Humes: 'It was crazy when Marvin and I first got together. A lot of girls loved him and I was dating him so I was really scared to go to shows'

BelfastTelegraph.co.uk

Rochelle Humes is in for a busy summer. Her publisher wants a second book by September. "I didn't know I was doing two!" laughs The Saturdays singer, her bare feet up on a chair in New Look's Oxford Street store, where she has been shopping for her daughters, Alaia Mai (6) and Valentina Raine (2). "I guess the first did better than expected."

Rochelle Humes is in for a busy summer. Her publisher wants a second book by September. "I didn't know I was doing two!" laughs The Saturdays singer, her bare feet up on a chair in New Look's Oxford Street store, where she has been shopping for her daughters, Alaia Mai (6) and Valentina Raine (2). "I guess the first did better than expected."

The pop star turned TV presenter's debut was published earlier this year. She wrote it in response to her eldest deciding she didn't like her curly hair because she "didn't look like a princess".

"It broke my heart," says Humes (30), who later realised that her daughters had only known their mother with straight hair. She vowed to embrace her natural curls as a New Year resolution last year and when she couldn't find a children's book to endorse the message decided to write one herself.

The Mega Magic Hair Swap! was published in February and tells the story of two little girls - one with curly and one with straight hair - who make a wish to swap their hair, but later learn to love their own. Writing the book was "self-indulgent - something for me and my daughter", says Humes, who is married to former JLS singer Marvin Humes, but it quickly became more than that.

Since she published the book, affected parents have come forward from all corners of society - a mother whose daughter always asked for "yellow hair"; an auntie whose mixed-race niece wanted to look more like her friends; parents whose child dreamed of looking like Rapunzel. After reading the book, that little girl told her mother: "I love my curly hair, it makes me, me."

On World Book Day in March, Alaia was "so sassy" that she decided to dress up as herself from the book - the curly-haired character is called Mai, her middle name - and children across the country followed suit. "I could not believe how many kids went as her," Humes says. She spent most of the day in tears.

Today, Humes is glowing, wearing a daisy-print jumpsuit from New Look - she is an ambassador for the shop. "Curly hair is my default now," she smiles, she blow-dried her hair for the Bafta TV Awards last week because "it's nice to have a change", but wants that to be the "unusual" look rather than the norm. Alaia helped her get ready for the awards and Humes shared an Instagram post with her 1.4 million followers admitting she doesn't always feel comfortable on the red carpet.

"It's an overwhelming experience," she says, describing how she spent the night fan-girling the Killing Eve cast. "There's nothing more…" she lets out a deep sigh of relief, "than the moment when you've finished the pictures and you're like, 'Okay, we can go in now'. It's a bit like being caught in headlights."

Fortunately, Humes is used to keeping her cool in front of a camera. She is currently in her fourth series as co-host of the ITV obstacle series Ninja Warrior and regularly guest presents This Morning alongside Phillip Schofield.

Last year, she stood in for five weeks while regular presenter Holly Willoughby replaced Ant McPartlin on I'm a Celebrity!, during which time she interviewed Theresa May. She laughs as she recalls the moment she gave the PM a hug. "She kind of just stood there," Humes told The Sun. "Afterwards, I was like, 'Oh, did I actually just hug Theresa May'? You know what though, maybe she needed the hug."

Did she feel imposter syndrome covering for Willoughby? "I didn't even know what (imposter syndrome) was," she says, insisting she and Willoughby are good friends and Schofield is "such a generous host". "What's funny is I was talking to Holly and she also had that feeling about filling Ant's shoes. I think everyone has that feeling to a degree."

Tonight is Rochelle's own moment in the limelight, it's the first episode of her and Marvin's debut standalone TV show as a couple - a primetime BBC1 music quiz show called The Hit List. Humes is hiring a cinema for all the family to watch.

How was their first experience working together? "We're still talking," she says cheerfully. "I actually found it easier because when you start something new and you're co-hosting, you have to get to know how they work - and there's none of that to do here."

Despite her fame, Humes normally forgets why people are looking at her in the street. "I'll think I must have a visible bogey or something," she laughs, though Marvin gets stopped a lot more. "It was crazy when we first got together," she says, recounting the time a moving suitcase in a hotel lobby turned out to contain a JLS fan. "There were a lot of girls that loved him and I was dating him, so I was really scared to go to shows. Some of them would be really nice to me, some of them would be like, 'You've ruined my life'."

At home in Epping, the couple split childcare as evenly as possible. Today, Marvin did the school run while Rochelle was at work - she has a baby monitor app on her phone and texted her husband before 8am to get Alaia out of bed - then Marvin leaves the house at 8pm for his radio show on Capital.

Humes does Pilates after the school run if she's free in the daytime, but admits finding time for exercise can be hard. She ran the London Marathon last year as part of her 30 before 30 bucket list (she turned 30 in March) and tries to eat healthily, but won't talk about weight or dieting in front of the girls.

"I do everything through teeth," she says. "If I know we've had a week where there's loads of kids' parties and cake, I'm like, 'We should be careful with this because we've got to go to the dentist soon'. I never do it with weight".

Humes and her husband watch Netflix together in their downtime, though Marvin "does cheat on me with box sets", she says. "We'll start something together and then he's like, 'Oh, you were working, so I stormed ahead'. He's seen everything. I'm like, 'where do you find this time'? He says I need to start taking my laptop out and watching shows in the back of taxis."

The upside of Marvin working late is it gives her time to watch Love Island. "That'll take over my summer," she chuckles, denying any rumours of her sister, Soph Piper, taking part in this year's series, which starts next month. "They're very much rumours. They did ask her and she was confused. But she's not, she doesn't want to do it."

Humes is also a fan of Big Little Lies and Killing Eve, both of which have second series coming next month. "June's a busy month for me," she laughs. Don't tell her publisher.